The present invention relates to the field of marine equipment, more specifically the present invention relates to the art of connecting tugboats or pusher boats with barges or other non-powered vessels which are equipped with a notch in the stem of the barge for receiving a tug or pusher boat therein.
The present invention generally relates to apparatus and methods for connecting tug boats or pusher boats to barges for transporting cargo on oceans, rivers, lakes and harbors. Barges, typically having no drive mechanism, rely upon tugboats or pusher boats to move the barge from one location to another. The connections between tugboats and barges have taken numerous forms over the years. The majority of forms involve interconnection between the tugboat and the barge by use of cables. Alternatively, the use of extendable ram devices on the tug which interconnect with receivers on the barge have been used to achieve a more stable connection.
An example of this extendable ram and receiver configuration is shown in FIGS. 1 and 2 wherein a tugboat or pusher boat 14 is connected to a barge 10. This connection is achieved by the bow of tug 14 entering a generally U-shaped or V-shaped notch 12 on barge 10. Once tug or pusher boat 14 is within notch 12, rams 16 are extended from tug 14 into receivers 18 of the barge. The rams typically have a hydraulic drive or screw drive mechanism and generate sufficient force to securely hold tug 14 within notch 12 of barge 10.
Referring now to FIG. 1, tug 14 is shown joined to barge 10 with rams 16 aligned and extended into receiver 18. It will be appreciated that in FIG. 1 that receiver 18 of barge 10 extends vertically throughout nearly the entire height of barge 10. The reason for this full height receiver is that as barge 10 is loaded or unloaded, its position with respect to waterline 20 will change. Therefore, tug 14 must be able to join with barge 10 at any position along the vertical height of barge 10. This is accomplished by having receiver 18 extend vertically along the entire height of the barge to account for changes in draft of the barge resulting from changes in the waterline 20 position with respect to the barge as a result of loading and unloading of the barge.
In the prior art, an early form of connecting a tugboat with a barge is shown in U.S. Pat. No. 3,512,495 to Fletcher in which a hydraulically extendable pin is mounted on the port and starboard sides of the bow of the tug, and the cylindrical pin of the tug is inserted into a circular receiver or housing mounted on the barge. An alternative form of coupler and receiver is found in U.S. Pat. Nos. 3,844,245 and 3,935,831 to Yamaguchi. In the Yamaguchi device the hydraulic ram mounted on the tug boat is equipped with a generally diamond shaped head or connector in which the top and bottom points of the diamond are truncated or rounded off. The left and right side points of the diamond headed connector of Yamaguchi fit into a receiver mounted on the barge which is equipped with projecting teeth that present indents therebetween. The indents are sized to receive the left and right side diamond head points of tug of mounted ram of Yamaguchi. Yet another alternative form of connecting tug boats with barges is shown in U.S. Pat. No. 4,688,507 to Kuhlman, et al. In the Kuhlman patent, the barge receiver portion is a vertical receiver or channel having spaced apart projecting teeth on either side of the receiver or channel. Into the receiver of the barge is fitted a connector, sometimes referred to as the ram head or helmet, which is mounted on the ram of the tug. The tug ram connector is equipped with three projecting teeth on the left and right side of the connector which intermesh with the teeth on the sides of the channel or receiver on the barge.
While each of these prior-art designs serves to connect a tug boat with a barge, each requires a substantial degree of alignment between the head of the tug ram and the receiver of the barge for an effective, secure connection to be made between the two devices. In the Yamaguchi design, the two opposed diamond points of the ram head must be aligned with the indented spaces between the projecting teeth of the receiver. In the Kuhlman design, the three projecting teeth on either side of the ram head must be aligned with the teeth and depressions of the barge receiver for successful connection. In either of these designs, a certain degree of realignment of the ram head is required of the tug boat operator to successfully complete the connection between the tug and the barge.
In the connection utilized in the Fletcher patentxe2x80x94a cylinder fitted into a circular receiverxe2x80x94a degree of undesirable play between the ram and receiver of Fletcher results since the size of the ram is less than the diameter of the receiving hole or void, there is play between the Fletcher ram and receiving void. Further, the Fletcher ram does not outwardly compress against a solid wall of the barge. Rather, the cylindrical ram is simply inserted into the hole. In Fletcher there is not a snug, lateral connection between the tug and the barge as is provided by the compressive fit of both Yamaguchi and Kuhlman.
The present invention achieves two principal advantages over the prior art: (1) a lesser degree of pre-connection alignment is required between the connector or ram head and the barge receiver of the present invention due to the pentagonal configuration of the connector and corresponding configuration of the receiver; and (2) the secure compressive fit between the port and starboard rams of the tug and the port and starboard receivers of the barge is achieved by the inwardly angled connector and receiver design which continues the compressive fit functions of Kuhlman and Yamaguchi while simplifying the equipment needed to achieve re-alignment of the connector prior to its engagement with the receiver.
These advantages and more are achieved by the connector or ram head and receiver of the present invention which comprise a ram connector that is mateable with the receiver of the barge, the ram connector having a generally pentagonal shape as viewed from the side elevation of the ram connector as it is presented to the receiver. The receiver of the present invention is adapted to mate with the generally pentagonal ram connector by having a configuration which comprises opposed side walls that are spaced apart to receive the generally pentagonal shaped ram connector therein. One of the side walls has a generally flat surface, and the opposed side wall has vertically spaced apart teeth or projections. In the space between two adjacent projections is received one of the edges or corners of the pentagonally shaped ram connector of the tug. The flat face of the pentagonally shaped connector which is opposite the connector edge that is captured between the projecting teeth is fitted against a flat receiver sidewall that is opposite the receiver sidewall having the teeth or projections thereon.
The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.